maointire



(No Model.) X 2 Sheets-Sheet 1.

G. R. MAGINTIRE. ELEGTRIG ARC LAMP.

No. 535,840. Patented Mar, 19,1895.

2 SheetsSheet 2.

' (No Model.)

G. R. MAGINTIRE. ELECTRIC ARC LAM Patented Mar. 19, 1895.

UNITED STATES PATENT OFFICE.

GEORGE R. MAGINTIRE, on NEW YORK, N. Y.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 535,840, dated March 19, 1895.

Application filed July 5, 1894 Serial No. 516,558. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE E. MACINTIRE, of the city, county, and State of New York, have invented certain new and useful Improvementsin Electric Lamps, (Case A;) and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, making a part of this specification.

Arc lamps, as ordinarily constructed, are open to various objections. By reason of the complicated mechanism which has been thought to be necessary for feeding or regulating the feed of the carbons they are not only heavy but require considerable space, so that for many locations, particularly where the ceiling is low, they are not available. Moreover the frame-work which supports the carbons and the feeding mechanism is commonly so constructed as to intercept the rays of light from the are at different points. Still again the feeding mechanism is usually so arranged that the carbon is fed by gravity or a spring under the control of regulating mechanism, in which case the corrosion or oxidation of the moving parts not infrequently prevents the proper feed of the carbon.

The object which was primarily in view in this invention was the production of an arc lamp which should be exceedingly compact and therefore available for use more generally than the arc lamps heretofore constructed. At the same time in making the lamp compact it has also been made of less weight than other lamps and it has been possible to reduce very much the area of obstructive parts and to dispense altogether with some portions of the supporting frame-work which have heretofore been considered necessary. At the same time the strength and durability of the structure have not been decreased but on the contrary have been increased.

A further object has been to so arrange the feeding mechanism that it shall act positively and at the same time shall permit the carbons to be advanced by gravity or by spring pressure.

Incidentally to these main objects various other features of improvement have been devised all of which will be fully described hereinafter.

shown in section, the globe holder being represented as broken out, a globe being shown in part and some other parts being broken out to save space. Fig. 2 is a horizontal section on the line wm of Fig. 1. Fig.3 is a detail view in vertical section on the line yy of Fig. 2, with a portion of the series coil and its jacket broken out. Fig.4 is a detail view in horizontal section on the line zz of Fig. 1. Fig. 5 is a detail view in elevation of a portion of the feeding mechanism.

The feeding mechanism and other parts of the lamp are supported upon or by a plate A which has cast with it or otherwise formed upon it an inclosed casing A which projects above the upper surface of the plate, being open beneath. A stud A is secured or attached to the top of this casing to receive a hook A by which the lamp may be suspended. Upon the plate A are secured the various parts of the feed controlling mechanism, hereinafter more particularly referred to, and these are covered and protected by a shell B. The mechanism referred to is thus completely inclosed and guarded from access of dust or moisture.

To the under side of the plate A, and insulated therefrom, is secured a rod or post 0 upon which is mounted the globe-holding ring D by means of an arm at and sleeve cl, the ring D encompassing the rod 0. A second but shorter rod or post 0 is also secured to the under side of the plate A, being insulated therefrom, and is adapted to receive a sleeve d which is attached to the globe-holding ring D, a latch 0 being secured to said post 0' and adapted to engage the sleeve d to maintain the globe-holder in its normal and elevated position.

The globe E may be secured to the ring D by set-screws c, c, or any other suitable means. -When the sleeve d is released from the post 0 the globe may be lowered below the extremity of the lower carbon holder until the sleeve d rests upon a shoulder c on the post 0, when the globe-holder can be swung to one side to permit it to be cleaned or the carbons to be attended to and yet will not be disconnected from the lamp. The lower carbon holder F is also supported by the rod or post 0 through an arm F. To the plate A is also secured radially in line with the rod 0 a sleeve or tube G which has a slot 9 extending from end to end. The lower end of the sleeve is steadied by the arm F, but is insulated therefrom. Within this sleeve or tube is mounted a shaft H having a shallow spiral groove h of steep pitch formed thereon. This shaft finds a bearing for its lower end in the cap G which closes the lower .end of the sleeve G, and extends through the plate A and for a short distance above it. Upon the shaft 11 is mounted a traveling nut H which is formed of a sheet of metal embracing the shaft and having its edges brought together to form an arm or web h which projects through the slot 9 and connects the nut, by means of screws 71 with a carriage I which encircles and is guided by the sleeve G and supports, through an arm 2', the upper carbon holder J. The pitch of the spiral groove h of the shaft H is such that the shaft might be rotated by the weight of the driving nut and carriage and therefore the action of gravity would effect the movement of the upper carbon toward the lower carbon. The carriage l is also constructed in such a manner as to prevent interference with its free descent by binding upon the tube or shaft and to prevent any movement of the upper carbon out of line with the lower carbon, beingin efiect a long sleeve embracing the tube and having a steady pin 2' which engages a groove 9' formed in the tube G opposite the slot 9 to guide and steady the carriage and prevent oscillation thereof on the tube. In this manner the carriage can be made to balance itself as nearly as possible without causing any binding on either tube or shaft while at the same time the alignment of the carbons is maintained, the weight of the lamp reduced and the cost of construction diminished. As suggested hereinbefore, however, the action of gravity is not alone relied upon but means are provided for effecting the positive rotation of the shaft. For this purpose the shaft has fixed upon its upper end a fine toothed ratchet wheel K which is adapted to be engaged and actuated by a springpressed pawl m carried by a sliding bar M which is pressed backward by a spring m and forward by the armature M of the shunt magnet M the armature being pivoted as at m to an extension m from the core of the magnet. The shunt wire is connected to the main line at any convenient point and thence to a back contact or carried by an insulated post m An insulated contact point m is carried by the armature M in position to complete the circuit from the back contact m and is connected to the coils of the shunt magnet M From thence connection is made to the other side of the main circuit.

A forked lever N, which is pivoted upon a suitable supporting post, embraces the shaft H just below the ratchet wheel K and at its other end is connected to the armature N of the series magnet N the latter being preferably of the variety known commonly as the iron-clad, the coils being inclosed by a jacket 02 which is connected to the core of the magnet. By means of the lever N the shaft H is lifted bodily when the current is completed through the series magnet and the carbons are thereby separated sufficiently for the formation of the are.

A short shaft 0 is mounted in a suitable bearing supported by the plate A, being provided at its lower end, below the plate A, with a thumb-piece O and at its upper end with an arm 0 having a tooth 0 The shaft is acted upon by .a spring 0 to hold the tooth O in engagement with the ratchet wheel K and thus to constitute a hold-pawl to prevent backward movement of said ratchet-wheel. By a partial rotation of the shaft 0, by means of the thumb-piece O, the tooth 0 may be made to engage the pawl m and disengage the same from the ratchetwheel to permit the free rotation of the shaft II when the carriage I is raised by hand.

The connection of the main line to the series coil might be made in any convenient manner but I prefer to establish such connection through a resistance coil of peculiar construction which is supported within the upper end of the shell B upon a plate or diaphragm B. This resistance coil P is formed by crimping a Wire, as indicated at p, the crimps lying in the same plane to constitute a ribbon which is subsequently coiled spirally about the axis parallel with the plane of the ribbon with insulating material 13' between the convolutions. This agreement gives a great extent of resistance wire in an extremely compact and convenient shape.

From the resistance coil P connection is established to the sleeve G and thence to the carriage I and upper carbon holder J. From the lower carbon holder connection is made to the rod 0 to which the outgoing leg of the circuit may be connected.

The operation of the lampherein described is in general the same as that of other lamps of like character and need not be set forth in detail herein. It will be observed that there is but one supporting rod 0 in line with the arc and that the sleeve G stands in the same plane with the carbons and said rod, whereby there is but a single lateral obstruction for the rays of light. Moreover there is no cap or other metal piece of large area below the light to cut off any considerable number of the rays of light. It will be observed also that the carriage I and arm 2' with the upper carbon holder J may be raised above the plate A by reason of the casing A with the open bottom, and a longer carbon thus be used than would otherwise be possible.

I claim as my invention- 1. In an electric lamp, the combination of a supporting plate, carbon holders supported by said plate, a single long rod secured to said plate, a globe-holder and a latch whereby the holder may be secured to said plate, and an arm secured to said globe-holder and havinga sleeve to encircle said single rod, whereby the globe-holder may be released from the plate and lowered upon the long rod and swung laterally thereon, substantially as shown and described.

2. In an electric lamp, the combination of a supporting plate, a single rod depending from said plate, an arm at the lower end of said rod,a carbon holdersupported by said arm, a slotted tube fixed to said plate radially in line with said rod and to said arm but insulated from the latter, a shaft mounted within said tube and having a spiral groove, of steep pitch means to rotate said shaft, a traveling nut mounted on said shaft, a long, sleevelike carriage mounted on said tube and connected with said nut, said carriage and tube being formed for engagement in a line opposite the slot to guide and steady the carriage and prevent oscillation thereof on the tube a carbon holder fixed to said carriage, and supported wholly thereby and independent electrical connections to said rod and tube, substantially as shown and described.

3. In an electric lamp, the combination of a supporting plate, a rod depending from said plate and supporting a carbon holder, a slotted tube also depending from said plate, a shaft mounted within said tube and having a spiral groove, means supported by said plate to rotate said shaft, a sheet of metal embracing said shaft to form a nut and having its edges brought together to form an arm projecting through the slot in the tube, a carriage encircling said tube and connected to said arm, and a carbon holder fixed to said carriage, substantially as shown and described.

4. In an electric lamp, the combination of a supporting plate, a shaft having a spiral groove supported by said plate, a traveling nut mounted on said shaft, a carbon holder connected to said nut, a ratchet wheel fixed to said shaft, a pawl and means to actuate the same, a short shaft supported by said plate and having an arm with a tooth to engage said ratchet wheel as a hold pawl and also to disengage the actuating pawl from said wheel, substantially as shown and described.

5. In an electric lamp, the combination of a supporting plate, having a casing extending upwardly with an open bottom, carbon feeding mechanism mounted on said plate around said casing, a shell inclosing said mechanism, a carbon holder, a carriage therefor, a guide for said carriage fixed to the top of said casing, whereby the carriage and holder may enter within said casing, and intermediate means to impart motion from said feeding mechanism to said carriage, substantially as shown and described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEO. R. MAOINTIRE.

Witnesses:

A. N. JESBERA, A. WIDDER. 

